Timing Belt replacement signs? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

As for the consequences for a failure, I've seen conflicting information as to whether the 4.7L V8 is interference or non-interference. My dealer's Service Manager told me it was non-interference, so I suspect the consequences of a failure is leaving you needing a tow at an inopportune time/place.
[/QUOTE]


Exactly my thought. I believe some older Honda's are trouble but not Toyotas.
 
I dont know of any obvious signs that a timing belt is ready to replace other than the mileage interval.

Remove the timing belt cover on the right side of the engine and do a visual inspection. It takes about ten minutes to remove the cover. Note: Right side is the passenger side for a left-hand drive.
 
My dealer recommends 105K for the V8 but 75K for the V6, saying from their experience, the V8 is easy on t-belts while the V6 is harsh on them. Both engines recommend 90K for changing the belts, but they say those are general toyota guidelines that are adjusted to how the belts wear for different engines, usage, and conditions.

Unless the PO used some very shoddy gas, my hunch is your fuel filter should be fine. I had the fuel filter in my 4runner changed at 17 yrs and about 140K mi, and didn't notice any difference. For the first 14 yrs/93K mi, the PO (father) used normal (Arco, mobil, shell) 87 octane. The next 47K mi used chevron 91 octane. Vehicle ran great before the fuel filter change, no difference after. If you have some reason to suspect your fuel filter is dirty/clogged, your injectors might also have problems. BTW, I have yet to clean my injectors at (now) 20 yrs., so far, so good (hope i didn't just jinx myself).
 
Last edited:
When you are talking "timing belt", is this the same as "cam belt"? Also, can you confirm that only the Land Cruiser 100 GX Diesel has a cam belt (that indeed needs replacing at a prescribed mileage), whereas the 100 GX Petrol has a timing chain. The timing chain is to be changed "on condition"; the mechanic can hear the specific noise from a timing chain that needs replacing. Is that correct?
 
When you are talking "timing belt", is this the same as "cam belt"? Also, can you confirm that only the Land Cruiser 100 GX Diesel has a cam belt (that indeed needs replacing at a prescribed mileage), whereas the 100 GX Petrol has a timing chain. The timing chain is to be changed "on condition"; the mechanic can hear the specific noise from a timing chain that needs replacing. Is that correct?

The timing chain will rattle upon startup when stretched. Once the oil pressure builds up, the tensioner takes out the slack and you shouldn't hear the rattle. If you do,it's a sign the chain/tensioner/guides/sprockets need replacing.

The only cases I've heard of timing chain failure is from tensioner failure or guide failure. I'm not sure about the guides in the 80, but in the 22r (4cylinder) hilux engines, toyota originally used a double timing chain with steel guides. Then they went to a single chain w/ steel guides, then to plastic guides. I've heard cases on the 4runner forums of the plastic guides failing, jamming the tensioner and causing the chain to fail, but one can get aftermarket steel guides for the 22r. You should be able to get 250K or so miles off the timing chain before replacement, but replacing it is a bigger job and there are more parts (guides, sprockets, tensioner, etc.) and more labor costs. One toyota tech told me the only time he's seen t-chain failure is from the tensioner failing from sludge.

Pricewise, it's about a wash. You have to do the t-belt twice as often, but it's less cost (dealer charges $1300 for the t-chain job [10 hrs labor @ $75/hr by the book+parts, but with shortcuts, it can be done in 4 hrs by a seasoned mechanic]; t-belt job is probably more like $700 or less?). The main advantage is the chain will start to rattle long before it fails, so you get some warning (how much, who knows?) One guy on the 4runner forum had that warning and tried to squeeze another month of driving out of it. During that month, it failed, chain sawed through the coolant lines in the head.
 
Generic question (applicable to other topics) but this thread is perfect:

Let's assume that the rig is out of warranty and it has 85k mile, say, i.e. before the timing belt is supposed to be changed. It breaks...! What would Toyota's position be, you think:
- sorry, you're SOL!
- this shouldn't have happened, we'll fix it for ya!
?

If the former, would one have a case to argue forcefully that they should fix it because it broke before "its time" ?

just curious
Eric

I have successfully had timing belts replaced by dealers in this scenario on a Pontiac and a Nissan. The GM dealer tried to claim it was a normal wear and tear belt that should be inspected and replaced such as the fan belt. I argued that it is an internal engine part that is a chain and gears on other GM engines. The Nissan was a blown oil seal issue that spread oil on the belt. The fools were going to reassemble the oil soaked timing belt on and give it back to me. I had to provide the service manager a basic lesson about stretching oil soaked belts and threaten to call Nissan USA about it. The van was less than 1000 miles from out of warranty.

We receive a small pamphlet about our warranty. The dealer has a shelf full of books to counter it. When pressed the GM dealer could not find an interpretation in the books that suggested the timing belt/chain was anything other than an internal engine part.
 
The timing chain will rattle upon startup when stretched. Once the oil pressure builds up, the tensioner takes out the slack and you shouldn't hear the rattle. If you do,it's a sign the chain/tensioner/guides/sprockets need replacing.

The only cases I've heard of timing chain failure is from tensioner failure or guide failure. I'm not sure about the guides in the 80, but in the 22r (4cylinder) hilux engines, toyota originally used a double timing chain with steel guides. Then they went to a single chain w/ steel guides, then to plastic guides. I've heard cases on the 4runner forums of the plastic guides failing, jamming the tensioner and causing the chain to fail, but one can get aftermarket steel guides for the 22r. You should be able to get 250K or so miles off the timing chain before replacement, but replacing it is a bigger job and there are more parts (guides, sprockets, tensioner, etc.) and more labor costs. One toyota tech told me the only time he's seen t-chain failure is from the tensioner failing from sludge.

Pricewise, it's about a wash. You have to do the t-belt twice as often, but it's less cost (dealer charges $1300 for the t-chain job [10 hrs labor @ $75/hr by the book+parts, but with shortcuts, it can be done in 4 hrs by a seasoned mechanic]; t-belt job is probably more like $700 or less?). The main advantage is the chain will start to rattle long before it fails, so you get some warning (how much, who knows?) One guy on the 4runner forum had that warning and tried to squeeze another month of driving out of it. During that month, it failed, chain sawed through the coolant lines in the head.



It seems odd to me that a chain would be so much more expensive than a belt to replace. Why the big difference?
 
I personally am not changing my belt I want to see how far I can make it on one!
 
You could do predictive maintenance by opening the passenger side belt cover and rotating the belt one full rotation. This is very easy to do. Takes about 10-15 minutes.
You just have to remove the air cleaner box and a few bolts holding the timing belt cover.

My belt shows no signs of wear at 105K miles.

Belt live would vary quite a bit depend on where you live. I think extremely hot and dry climate would takes its toll on rubber faster than normal climate. So does extreme cold.
DSCN11741.JPG
 
110,677 miles on original belt. Dealer changed water pump and timing belt for 592.95$. .🍺 The belt had had spots where it looked like the coating on the outside of the belt had worn off, looks like once that's gone the wear begins.
One tooth had signs of serious wear.

First 60k miles in Long Beach, CA. Easy city life. The last 50k miles in Death Valley and surrounding hell with at least 35k of that offroading.

On a side note the dealer placed some of the wiring so that it would rub against the serpentine belt and it was almost done cutting through the protective shielding after my wife returned from the shop with it. :mad: I spotted it within 10 seconds of looking under the hood and I'm certain that they did it intentionally.:cheers:
I'm never taking it to another mechanic again.!@#!@@
 
Last edited:
I work at a mine that has probaly 500 Toyota 105, 80 and 75 series cruisers. In 20 years of driving Toyotas at work I have heard of two timing belt failures. These failures occured with less than 5000km's on their clock. Obviously a bad batch of belts. These vehicles are left idling all day sometimes without being driven just to keep the airconds running. They are abused by some individuals. They take a hammering and somehow survive. This is why I bought one.
Anyway I changed my timing belt when I bought my cruiser at 50000km's just to be sure. I change mine every 70000km's now.
As said, pop cover and rotate one turn. Any damage seen I would replace although I have seen belts with teeth missing and badly cracked still holding together so damage can be quite servere.
 
Man, this thread is going for a record.

What are the signs the timing belt needs replacement? The odometer reads "90000", "180000", "270000", "360000" miles, etc.

There are some things that make sense to stretch maintenance intervals on. I don't believe the timing belt is one.

I'll say it again: A reinforced belt in tension derives most of its strength from the internal reinforcement. You cannot reliably predict failure by visual inspection of the belt exterior. Sure, failures near the change interval (90k) are rare - that speaks to the fact that failure impact is very severe, and probably also implies that belt failure distributions are widely-scattered, both necessitating extra margin of safety in underrating belt life & shortening the service intervals to make darn sure the belts never fail in service.

Y'all go ahead and run 'em past 90k if you want. Please post pictures of results if you break one. :)
 
Yeah well said. I wouldn't go 1km past the replacement interval. I think the timing belt is the most important maintenance item that cannot be overlooked.
 
After seeing my belt with its obvious wear I learned my lesson and will never tempt fate with the timing belt again, especially considering the relatively low cost of replacing it VS the motor. Just wanted to show what a belt over 90k miles COULD look like. Hell it might of looked like that for a long time before 90k. Good luck to anyone going over the recomended change interval, hope you have a fat wallet. Course my tranny failed so I was bound to have luck sometime :D.

Vampire<--- totally agrees with Tinkerer and awaits pics of the motor damage and belt breakage on the poor souls LC.:crybaby:
 
First 60k miles in Long Beach, ca. Easy city life. The last 50k miles in Death Valley and surrounding hell with at least 35k of that offroading.

Your experience shows that extreme climate shortens t-belt life, although you still got 20,000 miles over recommended. I went 115,000 on the orginal belt in a normal SE climate. Based on that belt looking like new and others posting a similar experience with similar mileage, I plan to go at least that again on this t-belt. I didn't change the water pump at 115,000 so that could go first. Time will tell. Now at 155,000.
 
Paging Miraloiza.....or Ppressle....

Pardon my noob mechanic skills and could you please explain how you rotate the engine to correct position?

How do you rotate the timing belt one full turn? Use the starter motor to try to get it to the desired position while the fuel pump relay is pulled out? Do you use a wrench to turn the drive shaft? Do you do it by hand (grabbing onto what?) while the transmission is in Neutral?

I have seen a bunch of posts about turning engine to certain number of degrees BTDC or ATDC, and rotating the belt to inspect it.
 
Paging Miraloiza.....or Ppressle....

Pardon my noob mechanic skills and could you please explain how you rotate the engine to correct position?

How do you rotate the timing belt one full turn? Use the starter motor to try to get it to the desired position while the fuel pump relay is pulled out? Do you use a wrench to turn the drive shaft? Do you do it by hand (grabbing onto what?) while the transmission is in Neutral?

I have seen a bunch of posts about turning engine to certain number of degrees BTDC or ATDC, and rotating the belt to inspect it.


When the belt is attached you simply rotate it with a socket on the crank or on one of the cam pulleys. Here's a few pics of when I did mine along with the starter a couple months ago:

https://forum.ih8mud.com/showthread.php?t=148025
 
I will join the majority who believe the timing belt can go a good bit longer than Toyota recommends. I live in the Southeast and recently changed my belt at 110,000. See my post in August 07. It was hardly worn. The water pump had no sign of wear, but I replaced it anyway.
 

Users who are viewing this thread

Back
Top Bottom